Modern standard definition digital video and television devices and, to a greater degree, high-definition (HD) digital video and television devices are being designed with increasingly higher video data or frame rates to provide high quality video to the user. Additionally, many advanced video processing techniques have been developed, for example three dimensional (3D) graphics rendering techniques, which require complex design and computation. As video data rates increase, sophisticated video processing algorithms such as graphics rendering become increasingly costly and difficult to implement.
Many video processing problems involve the processing of luminance (luma) and chrominance (chroma) components of the video frames, where luma represents the brightness or the achromatic component of the image, and chroma represents the color information. The human eye tends to be more perceptive to variations in brightness than color such that lower color detail can go unnoticed to a viewer. Thus, to reduce data rates and processing requirements, some conventional video processing systems operate on reduced resolution chroma signals. This is typically achieved by chroma subsampling, or mild down sampling of the chroma components at ratios of 2:1, 3:1 or 4:1 in a vertical and/or horizontal direction within each frame. However, chroma subsampling can cause artifacts in images causing them to appear fuzzy or blurry, particularly in areas of high detail. Moreover, down sampling of chroma data generally does not sufficiently decrease the load on complex video processors under high video data rates.
Accordingly, there is a need for high quality video processing with reduced computational complexity.